A symposium on embryo-maternal relationships and lectures on the state-of-the-art of nuclear magnetic resonance (NMR) imaging and spectroscopy will be part of the program of the 20th annual meeting of the Society for the Study of Reproduction. The meeting is scheduled for July 20 to July 23, 1987 at the University of Illinois, Urbana-Champaign. The meeting is somewhat special in that this meeting is the 20th anniversary of the founding of the Society at the University of Illinois. The relationship and interaction between the embryo and the mother has been recognized in the past but very poorly understood. Only recently have techniques been developed and studies done that may help explain why certain genetic combinations of mother and embryo survive and others are less likely to. The success of a particular mating in domestic animals or an embryo transfer in humans and other animals depends on embryo-mother compatability in time and development. Dr. Carol Warner, Iowa State University will discuss the genetics of rates of development in mice, pigs and chickens on survival of embryos. Dr. Gary Anderson, University of California, Davis, will present information on incorporation of genetic material into embryos and subsequent development. Dr. Alan Beer, University of Michigan, will be the moderator. The use of NMR in non-invasive imaging and spectroscopy has made tremendous strides in the last few years. The potential for monitoring, diagnosing and measuring by NMR is very exciting. Dr. Paul Lauterbut, University of Illinois will speak to the new developments in NMR imaging, Dr. Joan Dawson, University of Illinois, will discuss use of NMR spectroscopy in monitoring changes in reproductive organs and Dr. Don Mattison, University of Arkansas will describe work on NMR in fetal and placental physiology. Dr. Florence Haseltine, Center for Population Research, NIH, will be moderator.